Humanoid robotic systems may have a structure that resembles a human body. An example humanoid robot system may have a robotic head, two robotic arms, a main robotic body, and two robotic legs. Such a robotic system may stand with the two robotic legs. For example, each of the robotic legs may include a robotic knee, a robotic ankle, and a robotic foot. The robotic legs may stabilize the robotic system. For instance, one of the robotic legs may bear the weight of the robotic system while the other leg swings forward to take a step in a given direction.